Refer to the exhibit. A network administrator is troubleshooting a BGP adjacency issue between routers R2 and R5. R2 uses loopback0 interface 2.2.2.2 and R5 uses loopback0 interface 5.5.5.5 in the neighbor ip_address remote-as as_number statement in the configuration. However, an adjacency does not form. Which action can the administrator take to resolve the issue?

Question:

Refer to the exhibit. A network administrator is troubleshooting a BGP adjacency issue between routers R2 and R5. R2 uses loopback0 interface 2.2.2.2 and R5 uses loopback0 interface 5.5.5.5 in the neighbor ip_address remote-as as_number statement in the configuration. However, an adjacency does not form. Which action can the administrator take to resolve the issue?

• Add a static route on R5 to reach IP address 2.2.2.2.
• Issue the neighbor 5.5.5.5 remote-as 65501 command on R2.
• Add a default route on R2 toward R5.
• Ensure that the interface with IP address 10.1.45.5 is up/up.

Explanation: Two BGP routers do not have to be directly connected or in the same subnet to form a BGP neighbor relationship; however, Layer 3 connectivity is required. For a router to have Layer 3 connectivity to the neighbor, it needs to have a route in the routing table that points to the neighbor router. The fact that there is no route in the routing table on R5 to reach 2.2.2.2 and R5 can ping R2 with the ping 2.2.2.2 source 5.5.5.5 command indicates that R5 can reach R2 via the default route configured on R5. BGP does not consider the default route a valid route for forming an adjacency.

Exam with this question: CCNP Enterprise: Advanced Routing (Version 8.0) – BGP Exam